Document peotectob



Jan. 27, 1931. l. H. wlLsEY DOCUMENT PROTECTOR Filed June `28, 1929 Ivm Ji wv'wqa Patented Jan.V 27, 1931 IRVEN H. WILSEY, OF CHICAGO, ILLINOIS DOCUMENT PROTECTOR Application led June 28,

The invention relates generally to a document protector and, more specifically, to a device for preventing the alteration of writ-t ten or printed documents without noticeably distiguring said document.

It is air'object of the invention to provide a novel device of this character which is simple in construction, easy to operate, and ywhich alters the body of the document, after lo it has been completed, in a i'nanner which is ordinarily unnoticeable to a casual observer but which becomes strikingly lapparent if an attempt is made to alter, erase, insert or in any way change the original writing.

Another object of the invention resides in' the provision of a document protector embodying a means for perforating the portions of the document to be protected with countless numbers of almost invisible punctureskl dispersed throughout the entire treated surface.

Other objects and advantages will become apparent 4in the following description and from the accompanying drawings, in which:

Fig. 1 is a central vertical section of a, device einbodying the invention and is taken substantially along the lines 1-1 of Fig. 2.l

Fig. 2 is a plan view of the device, the cover being removed to disclose the general arrangement.

Fig. 3 isa transverse section taken on the lines 3-3 of Fig. 1. Y

Fig. 4 illustrates a document before .andq afterit has been subjected tothe action of the device.

Fig. 5 is adiagram of the electric circuits. In general, theorganization of the device comprises Aa. housing or casing which is constructed to provide -al passageway or channel through which the document to be treated maybe passed. On opposite sides of the,pas sageway elongated electrical conductors are mounted in opposed relation to each other. said lconductors being connected to a source 25 of high potential current arranged to produce a series of sparks between the conductors which are capable of perforating an interposed document. In addition, the conductors are arranged for rapid relative inovenient so that the sparks will be successively 1929. Ss'ial No. 374,573.

discharged at different points on the cond uctors thereby producing what may be termed a. series of sparks traveling along the conductors. In consequence, the relative movenient of the conductors beingrapid, the series of sparks traverses and perforates the entire .surface exposed to the action thereof.

More particularly describing the inveiition, the. drawings illustrateJ a preferred form of device by which the objects of the invention may be attained. Referring thereto, lrindicates Vgenerally the bottom section, and 1()a the top section, of a casing which encloses and support-s the operating parts of the device. The bottom section 10 has a basel l1 formed preferably of a dielectric material, and side and end'walls 12 and 13, respectively. The side and end walls may be formed of a single piece of material properly shaped and secured to the base. j

Mounted within the bottom section, and at opposite-ends thereof, are supporting blocks 14, 15 also of dielectric material. One of the blocks, in this instance the block 14 (Fig. v1) is of less height than the adjacent end Wall and is substantially '1 -shaped so that when assembled the short leg 16 of the block extends inwardly of the casing. A pair of upright-'pieces 17 (Eig. 3) aresupported ou -the upper surface of the leg 16 adjacent the inner edge thereof, which pieces are of sucli width that there is a gap 17 of substantial size therebetween.

The upper face of the bottoni section is arranged to be substantially closed by means which provides a surface over which the document to be treated may pass. For this purpose a pair of elongated rips18 (Fig. 3) rest, at one end, upon the upper surfacesof the upright pieces 17, and at the other end Y.

within recesses formed inthe end block 15. The strips 18 exteiid longitudinally of the bottom section and the upper surfaces of the strips are substantially flush with the upper Vedges of the side Walls of the casing. In width the strips are somewhatwider than the width of the upright pieces 17, but their adjacent edges are spaced/apart to provide a gap 18 therebetween which extends longi- 'bottom section when the open faces of the two sections are brou ht together. Within the top section and ad] acent the ends thereof are crossbars19, 20 of dielectric material positioned to engage the up Y the strips 18,-above the uprig t pieces 17 and the end bloc-k 15, respectively. Suitable means, such as the lscrews 21, are employed to secure the two sections together and for convenience these screws may also serve to hold the strips 18 at each end and the upright ieces 17 at the one end (see Fig. 3) in assem led relation. The side edges of the top section intermediate the cross-bars 19, 20 are recessed or cut away, as at 22, to lprovide a transverse document passage or slot (Fig. 1) through the casing across the upper surfaces of the strips 18 and the intermediate gap 18'1 therebetween.

Referrln to the construction of the electrical con uctors, it is contemplated that the desired end may be effected in various other ways but I have found that highly satisfactory results may be obtained by placing a rotating conductor adjacent but spaced from'a stationary conductor. By forming the rotatingvconductor in the shape of a spiral, the adjacent edges of the two conductors may be said to have an angular rather than a parallel relationship, in consequence whereof movement of therotary conductor causes the oint of closest proximityof the edges, whic of course, is the point at which a spark will jump to move rapidly and recurringly the length of the stationary conductor.

The articular `construction and arrangement o the conductors may be seen in Figs.

1, 2, and 3. A narrow, elongated strip 23, of

some metalwhich is a good conductor of eectricity, is twisted into a spiral form. l'referably, the strip is twisted throl'lgh 360 or one complete turn, the purpose of which will later become apparent.4 A bearing pin 24 Fig. 1) is secured on one lend of the strip 23 in axial alinement therewith, and aI bushing 25 is mounted in the end block 15 to receive said pin. The bushing is centrally loy cated with respect to the gap 18l between the two strips 18, and is so positioned adjacent 1 the upper edge of the end block 15 that the periphery of. the cylindrical area, described in the rotation of the spiral conductor, is substantially tangential to the upper plane surfaces ofthe strips 18.

, The spiral conductor 23 is driven by an electric motor which, while shown herein as being mounted outside of the casing by means of brackets 27 secured to the casing, may of A er surfaces of l course be otherwise arranged. When the motor is so mounted the armature shaft 28 thereof extends into the casing in substantial a-linement with the oppositely disposed bushing 25. The spiral conductor 23 extends longitudinally of the casing to position the other end in the gap 17Il intermediate the lupright pieces 17 and an insulating member 29, also extending axially of the spiral conductor, is rigidly secured thereto. The free end of the insulating member 29 isrecessed to receive'f and be secured to the end of the motor shaft 28, forming a driving connection between the motor and the spiral conductor.

The top portion 1()a of the [casing carries the stationary conductor, which in the present instance comprises two separate conductors arranged to cooperate with the rotating con-- ductor to increase the number ot' spark discharges. Thus, midway between the ,two cross insulating bars 19,20 a third insulated cross-bar 3() is secured .which supports one end of a pair of straight conductors 31, 32

extending to the other cross-bars 19, 20 respectively. These conductors are mounted in end to end alinement but are separated andinsulated from each other by the median cross bar 30. "With respect to the other parts of the device, the exposed edges of the straight conductors are substantially in the plane of the upper side of the slot through the casing, and the 'conductors lie immediately above and parallel with the axis of the spiral conductor 23. In consequence of this construction, in every position of rotationv of width and depth to raccommodate, an induc tion or spark coil 33 of any' well known type. A condeljiser 34 may also he contained within the casing, if desired, and, where used, is preferably interposed in the circuit leading lthe spiralconductor, there will be a portion` to the primary coil of the spark coil. The

secondary or high-tension circuitof the spark coil includes the rotating and the stationary conductors, the space between said conductors forming a spark gap in the secondary circuit. ln the present instance the connections are such that there are virtually two spark gaps, thereby doubling the number of sparks perforating the document. 'lo this end, one of the secondary terminals is connected to the stationary conductorl 31 and -the other secondar terminal to the othery stationary con uctor 32 by suitable leads 35,36 (Fig. 5). Consequently, since the rotating conductor may be said tovbe common to both stationary conductors, an electric current traversing the secondary circuit passes from one stationary conductor across the separating gap to the rotating conductor, back across the gap to the other stationary conductor` to return to the other secondary terminal. 'Ihe discharges, therefore, occur at two points, which points, when the rotating conductor is in motion, move simultaneously from end to end along the stationary conductors. Hence, if a document is passed through the slot in the casing, as shown in brokenontline at 37 (Fig. 2), substantially the entire document will be perforated by the discharges passing between the conductors. A furtherv advantageous feature of the spiral shaped conductor 1s that of safety lsince the rapid rotation of the spiral produces a fanning y i, cidental or unintentional operation thereof when not in use. For this purpose, a rod or shaft 38 extends throughthe casing and bearsy in the cross-bars 19, 20 and 30. The outer end of the rod is bent to form a crank 39 for rotating the shaft. The inner end of the shaft 38 extends into the small compartment defined by the walls of the casing and the cross bar 19, uprights 17, and the leg 16 of the L-shaped end4 block. An insulatlng bushing 4G 4is snngly but rotatably mounted on this end of the shaft and in turn carries a metallic v sleeve 41 (see Fig. 3) which has two switch fingers 42, 43 extending radially therefrom.Y

I Preferably the sleeve 41 and the fingers 42,

43 are integrally formed of a somewhat resilient metal. Contact points 44, 45 (Fig. 2) are supported by an insulating bracket 46 mounted on the upper surface of the leg 16l plied to the crank 39 to close the switch, a

circuit is established through the contact points 44, 45,'switch lingers 42,43 and sleeve 41. As soon, however, as the crank 39 is released, the resiliency of the switch fingers moves at least one of 'the fingers away from its corresponding contact point to break the circuit and stop the device.

Inasmuch as the shaft 38 is capable of further rotation after contact, has been established, the shaft may be employed to feed the document through the passageway by providing one or more cylindrical rollers 38, of a resilient material such as rubber, firmly mounted at intervals on the shaft 38, and of such diameter as to engage the surface of a document passing over the sur-face of the underlying strips- 18. Continued rotation of the shaft 38, then, will feed the document through the device, the bushing 40 meanwhile slipping on the shaft without interruption of the established circuit until the shaft 38 is released.

In Fig. 4 I have shown on a somewhat emphasized scale a comparison between a'treatcd, unaltered portion of a check, indicated at A, and a portion ll on which an alteration has been attempted. The unaltered portion A presents. to an ordinary observer` the normal appearance of a check. However, if the check isscrutnnzed closely. or 1s held to the light,

countless numbers of very fine Aperforations may be seen, and under a magnif ing glass it may be seen that the paper at the margin of each hole is charred. If an erasure is attempted the charred margins break away kto enlarge the size of each perforation and make themplainly noticeable, even to a casual observer. Where the alteration attempted conlsists merely in writing additional words or characters, or in writingover a blank where a previous writing has been .removed by chemicals, the ink fills each orifice and a very noticeable blurred mark, as shown in B, results. Or the pen-point may catch in any of the holes to produce the lsame effect. viously, if the attempt to add written words is made over an erasure, the evidence of alteration is intensified.

It will be apparent from the foregoing description that a device has been produced which is capable of rapidly treating a written instrument so that any attempted alteration thereof must fail, which device is simple in construction and operation and may be mannfactnred for sale at a low cost.

I claim as my invention:

1. A document protector comprising, in combination, a casing having a passageway extending transversely therethrough, means within said casing providing a plane surface flush with the lower edge of said passageway, said means having a longitudinally extending gap therein interrupting said surface, a pair of elongated stationary conductors in said casing mounted in spaced relation to said plane surface above said gap therein and alined in end to end relation, means for insulating said conductors from each other, a rotating conductor mounted in said casing with the upper periphery of rotation lying substantially flush with said plane surface, said rotating conductor being spiral in form and arranged so that a point on said conductor is at all times adjacent to some one point on each of said stationary conductors, l

an electric -motor for driving said rotating conductor, au induction 'coil mounted in said casing, electrical connections extending between each end of thev secondary circuit of said induction coil and one of the stationary conductors, other leads connecting the motor and the primary circuit of said induction coil in parallel to a source of current, and a control switch interposed in said last m/entioned leads.

2. A document' protector comprising, in combination, a casing having a passageway extending trans\-'ersely therethrough, aspi rally formed conductorrotatably mounted within said casing'adjacent onel side of said passageway. a stationary conductor paralleling said spiral conductor adjacent the oppo-u site side of said. passageway, and means for efecting electric spark discharges from one conductor to the other ,during the rotation of said spiral conductor.

3. A document protector comprising, in combination. a support, a conductor in the form of a spiral member rotatably mounted on said support. a second conductor rigid with saidl support and mounted ,invparallelism with the axis of rotation of said spiralv conductor, said two conductors being spaced apart a' short distance to constitute a spark gap, and an electrical circuit including said van interposed document.,

two conductors for eifectingelectric discharges across said spark gap to perforate 4. A document protector comprising, yin combination, a support, a conductor in the form ot' a spiral member lrotatably mounted on said support, means for rotating said spiral conductor, a'second conductor rigid with said support and mounted in parallelism with the axis of rotation of said spiral conduct or, said two conductors being spaced apart a short dist-ance to constitute a spark gap. an electrical circuit including said two conductors for effecting electric discharges across said vspark gap to perforate an interf posed document, and means for feeding a document between said conductors.

5. A document ,protector comprising, in combination` a support, a conductor in the form ot a spiral strip rotatably mounted on said support, a straight. conductor rigidly mounted on said support adjacent but spaced from said spiral conductor and in parallelism with the axis thereof, an electrical circuit including said two conductors and arranged to effect the discharge of a series of sparks across the intervening gap between the straightconductor and the most adjacent portion of the spiral conductor, and means for rotating said spiral conductor so that said most adjacent portion thereof travels from end to end of the straight conductor.

6. A document protector comprising, 1n combination, a support, a rotary conductor mounted on said supportfalpair of elongated conductors mounted in end to end alinement.

adjacent said rotary conductorand paralleling the axis thereof, said rotary conductor being in the form of a spiral having one portion thereofv adjacent a portion of each of said elongated conductors to constitute two spaced spark gaps, an electrical circuit in-. cluding said two stationary conductorsand said rotary'conductor and arranged to-efect the discharge of av series of sparks across both of said spark gaps, and means for driving said rotary conductor to produce a shifting movement of the spark gaps from end to end ot' the elongated conductors.

7. A document protector comprising, inv

between said conl face, a second `elongated member mounted,

for rotating movement in said' gap and including a peripheral portion of current conducting'material in the form of a spiral, means for rotatingsaid last mentioned elongated member, means for effecting electric discharges between saidtwo elongated members, and feeding means for passing a. document across said surface between said tu'o members. i

9. A document protector con'iprising, in'

combination, a supporting surface having a.

longitudinally extending gap therein, Yany elongated member of current-comlucting material mounted to extend parallel to said gap and in spaced relation at one side of said surface, a second-elongated member mounted foi-rotating movement in said gap and including an elongated peripheral portion of current-conducting materlal in the form of a spiral, means for rotating said last mentioned elongated member, and means for effecting electric discharges between said two elongated members.

10. A document protector comprising, in combination, a supporting surface having a longitudinally extending gap therein, a pair of relatively movableelongated conductors mounted to extend longitudinally of said surface in said gap and positioned one on either side lof said supporting surface, said conductors having-XV their adjacent portions in angular relationship to provide a-spark gap therebetween at al-single point, Vmeans 'for iso effecting electric discharges across said gap,

tion of a pair'of elongated current-conduct-` ing members mounted for relative movement in spaced relation to each other, said memgap, and means bers having an angular relationship to provide a single adjacent point therebetween constituting a spark gap, and means for effecting relative movement between said members to produce a change in position of said spark O'ap. I

a 12. Ina document protector, the combina-.

tion of an elongated conductor, a second conductor mounted in spaced relation to said first conductor, and means for moving one of said conductors relatively to the other, said conductors being constructed so that at least the adjacent portions thereof have an angular relationship whereby said relative movef ment efects'a shifting of the position of the adjacent portions.

- 13. A document protector having, in combination, a pair of electrical conductors mounted in spaced relation to form a spark for moving said conductors relatively to each other to vary theposition of said spark gap.

14. In a document protector, the combination of a pair of electrical conductors mounted in spaced relation to'form a spark gap through which a document may be' passed, and means for relatively moving said conductors to effect a movement of said spark gap transversely of the direction of movement ofthe document.

15. 'In a device of the character described, the combination of means definingl a guide for a document to be treated, a pair of electrical conductors mounted adjacent said guide and spaced apart to form a spark gap through which said document must pass, and means forl producing a rapidly recurring movement of said spark gap transversely of said passageway.

16. A device of the class described having, in combination, a plurality of electrical conductors mounted in opposed spaced relation l to provide a spark gap therebetween, a high potential circuit in which said conductors are included whereby to cause sparks to jump between the opposed conductors, the device being constructed to permit a sheet of paper to be drawn through the spark gap between said conductors, and means for effecting a I movement of at least a portion of said conductors to eifect a shifting of the sparks relative to the document during the passage o the document through the device.

17. A. device of the character described having, in combination, electrical means providing a gap through which sparks are caused to jump, said means being constructed -to permit a sheet of vpaper to 'be drawn through said gap, and means for causing movement of said electrical means to shift the vice.

18. A device of the class described having,

4in* combination, a high potential electrical means providing a spark gap through which a sheet of paper may be drawn, and means for eifecting rapidly recurrent transitory movements of the sparking area to form. closely spaced minute perforatons throughout a large area of the paper. 1 9. A device ofthe character described having, in combination, a plurality of electrical conductors mounted in opposed spaced relation to provide between them a spark gap through which a document may be passed, a high potential circuit in which said conductors are included whereby sparks will be caused to jump between the oppod con! a ductors and through the document, and

meansv for effecting a traverse of the sparks in a direction transverse to the direction of movement of the pa r and thereby form minute perforations t roughout a large area of the document.

2Q. In adevice of the character described having, in combination, a plurality of elecacross ,said spark gap, and means for feeding a document through said spark gap.

21. In a device of the'character described having, in combination, a plurality of electrical conductors mounted in opposed spaced relation to provide therebetween a spark gap through which a document may be paed, a high `potential circuit in which said .conductors are included-for producing the passage of sparks across 'said spark gap, and switch means for controlling the flow of current through said high potential circuit.

22. In a device of the character described having, in combination, a plurality of electrical conductors mounted in opposed spaced relation to provide therebetween a spark gap through which a document may be passed, a high potential circuit in which said conductors are included for producing the passage of sparks across said spark gap, means for feeding a document through said spark gap, and a control switch for said high potential circuit connected to said feeding means for movement into circuit closing position during the feeding operation of said feeding means.

23. In a device of the character described having, in combination, electrical means providing a ga across which sparks are caused to jump an arranged to permit a document tobe drawn through said gap, a feeding means for drawing said document through said y gap, a switch for controlling the passage of electric current through said electrical means,

means: connecting said switch andl said feed-` in operation, and means yieldingly resisting said circuit closing movement to effect an automatic circuit interrupting movement thereof substantially at the moment-(said feeding means ceases to operate.

24. A method of treating written docu- I' ments which comprises passing the ndocument through a spark gap vprovided between two opposed spaced electrical' conductors and causing sparks to jump from one conductor to the other through the document to perforate both the Written and unwritten areas of the document.

InV testimony whereof, I have hereunto aixed my signature.

IRVEN H. WILSEY.v

lng means to move said switch intov a circuit v closing position While sald feedmg means 1s 

